According to police, a small explosion was set off at a U.S. military recruiting center in New York Times Square early Thursday. No injuries were reported.

For more than two hours, New York City police officers and firefighters cordoned the area after the explosion, allegedly a manmade device, was detonated at the Armed Forces Recruiting Center on the traffic island located on the 43rd and 44th Streets, Seventh Avenue and Broadway around 4 a.m., the New York Times reports.

By 6:45 a.m. traffic around Times Square was permitted and the subway service was restored after a temporary interruption.

The area was initially blocked by police as a precaution to make sure that there isn’t a second device or any other threat.

According to police, the explosion made a hole in the front door of the recruiting center.

Spokeswoman for the United States Department of Homeland Security, Laura Keehner, in Washington said that an investigation was on whether the attack was a terrorist one.

The subway service was restored by 5:39 a.m. including the A, C, E, N, Q, R, W, S and Nos. 1, 2, 3 and 7 lines. They were suspended by 4:24 a.m. including the Nos. 4, 5 and 6 lines.

Two hours after the explosion police officers were still turning cars and people from the site of the accident.

Much of 41st Street, Seventh Avenue and the subway station entrances were cordoned by police.

Traffic was diverted for a period to the west, at Eighth Avenue and 41st Street, where the avenue was blocked by a police van with traffic diverted through the Port Authority bus terminal.

Around 6:30 a.m. traffic on Eighth Avenue was moving more easily.

The recruiting station which was the target of the attack is the third standing there since 1946. It has witnessed regular antiwar protests since the start of the Iraq war in 2003. Even so, until today it hasn’t been attacked.

It was reopened in September 1999 after it was redesigned Stephen Cassell and Adam Yarinsky of the Architectural Research Office for a $ 1 million. Inside you can find space for Army, Navy, Air force and Marine recruiters and a bathroom.